Nepean weather
Loading live data…Clear,warmer tomorrow
Env. Canada, the European and the American model put Nepean's high today between 10° and 14°, a 3° split. Tomorrow: cloudy, around 16°, with a 1% chance of rain.
Latest for Nepean: Env. Canada (GEM model): 0° Clear · European (ECMWF): 3° Partly cloudy · American (NOAA GFS): 0° Clear.
CheckWeather.io on iPhoneFree. No ads, no account.Nepean weather in numbers
measured normals and 10 years of recorded weatherNepean swings 39°C across the year, from 26°C highs in July to -13°C lows in February, and September is usually the wettest month in a year that brings about 984 mm of precipitation. Over 10 years of recorded weather it averages 65 days a year at 25°C or above, 13 of them at 30°C or above, 149 frost nights, and rain on 141 days.
Day counts are from the ERA5 reanalysis for Nepean’s grid square, 2016 to 2025, counted the same way for every city so the numbers compare. A reanalysis square is an area, not a weather station, so it is good for counting days and not for a single day’s record.
The weather map: all three models at once
Env. Canada, European, American side by side around Nepean and nearby towns.Live rain radar →Nepean hourly forecast: next 14 hours
consensus of the three modelsRain in the next 24 hours, model by model
each model's own hourly precipitation, side by sideLoading the three models…
Nepean 10-day forecast, out to 14 days
where the models agree, and where they splitNepean, Ontario is at its warmest in Jul (average highs near 26°C) and coldest in Feb (lows around -13°C), with roughly 984 mm of precipitation across the year. Below, compare what Env. Canada, European, American forecast for Nepean right now, and see exactly where they disagree.
We grade every model against the weather that actually happened, so you can see which forecast model is most accurate in Canada before you trust any single number.
Nepean climate by month
average daytime high and overnight low across a typical year (1991-2020)Source: 1991-2020 averages, ERA5 for this place adjusted with NASA POWER.
How the weather around Nepean has changed since 1995
Nepean sits in the same roughly 50 km square of NASA's reanalysis as Ottawa. That square shows no clear change in temperature between 1995-2004 and 2015-2024. See the full 30-year picture on the Ottawa page.
Which forecast is most accurate in Nepean?
CheckWeather Score, graded against the weather that actually happened
The CheckWeather Score blends temperature, wind and rain accuracy, each measured against ERA5 (the recorded weather) over the last 30 days across 1320 cities. Lower error means a higher score. See which forecast model is most accurate in Canada, how we measure forecast accuracy, or which model each weather app uses.
What do you think of the forecasts?
your vote countsThe accuracy above is the measured record. This is your opinion: which forecast service do you trust most in Canada? Give each 1 to 5 stars.
One vote per service. Anonymous: we store no personal data, only a one-way hash of your connection for a day to stop double votes.
Where the models disagree
temperature and rain, judged separatelyThe models often agree on temperature and still split on rain, and rain is usually what decides whether a plan survives. A wide rain range means the shower is genuinely uncertain, not that the forecast is wrong.